IDSA 2011: Vaccine Perceptions in the Physician Community

BOSTON--A press conference this morning at the 49th annual meeting of the Infectious Diseases Society of America highlighted two studies on physicians’ perceptions of vaccines: one on doctors’ own beliefs on vaccine safety and efficacy, and one on pediatricians’ experience of parental resistance to vaccines.

The press conference’s moderator, Bruce Gellin, MD, director of the National Vaccine Program Office in the Department of Health and Human Services, opened by explaining that physicians are well known to be the most important source of information on vaccines for the public, making the results of these studies extremely important.

The first study found that physicians who have graduated from medical school more recently are more likely to perceive vaccines in general as less efficacious and some vaccines as less safe than physicians who graduated from medical school decades ago. Study co-author Saad Omer, PhD, assistant professor of global health, epidemiology, and pediatrics at Emory University, explained that it is well known that as vaccination programs mature and direct experience with vaccine-preventable diseases fades, members of the public become more concerned with the perceived danger of vaccines. His study aimed to determine whether the same was true of physicians.

The study was based on a 2005 cross-sectional survey of 551 primary care physicians broken up into cohorts based on when they graduated from medical school—ranging from the early 1960s to the early 2000s. It found that overall support for vaccination remains high, but that more recent graduates were 15% less likely to believe that vaccines are efficacious compared with older doctors. Younger doctors were also more likely to believe that vaccines do more harm than good and had lower odds of believing that the inactivated polio, oral polio, MMR, and varicella vaccines are safe.

In response to a question from HCPLive, Omer explained that the study had not investigated whether there was a difference in attitudes of physicians within a given cohort based on whether they had direct experience with vaccine-preventable diseases and added that it would be an important area to investigate in future research. In response to other questions, Omer noted that the vaccines that prompted the most safety concerns are not among the newest vaccines, which typically inspire heightened skepticism, nor were they all live attenuated vaccines.

The second study surveyed pediatricians in nine Midwestern states on their experiences with parents’ refusing or delaying recommended vaccinations. Chris Harrison, MD, and Thomas Tryon, MD, both of the University of Missouri-Kansas City School of Medicine, explained that the results of the survey were very similar across the nine states surveyed—except for the rates at which pediatricians reported discharging patients from their practices over parental refusal to follow vaccine schedules.

The study was based on an online survey completed by 909 pediatricians. In all nine states, pediatricians reported that the vaccines most frequently deferred or refused were for MMR, HPV, and influenza. The top three reasons for refusal or deferral in all states were fear that autism would be caused by vaccination; that too many vaccinations were being administered at once, overloading the immune system; and that vaccines can cause severe side effects. The top three responses to vaccine-hesitant parents by pediatricians in all states were engaging parents in conversation about the benefits of vaccines, referring parents to evidence-based websites, and providing parents with evidence-based literature.

Providers reported that between 1% and 50% of parents delayed or altered the recommended vaccine schedule and 0% to 40% of parents refused at least one vaccine. The majority reported less than 5% overall refusal and under 20% schedule alteration, though some reported much higher rates.

The greatest variability from state to state was in the portion of pediatricians who said they would “fire” parents who refused to follow the vaccine schedule. This ranged from 0.9% in Minnesota to 38% in Iowa, with an overall average of 21%. In response to a question from HCPLive on why the discharge rate ranged so dramatically from state to state, Harrison noted that it was intriguing that in Minnesota, where the discharge rate was the lowest, the rate of vaccine refusal and deferral was the highest, while in Iowa, where the discharge rate was highest, the refusal and deferral rate was the lowest. The troubling implication of these findings is that as parental resistance to vaccines increases, pediatricians grow less likely to insist that parents follow the schedule.